http://s1133.photobucket.com/albums/...&current=2.jpg Looking at the afr curves above, what would be the obvious culprit? Really appreciate if anyone could shed some light...Thanks in advance. Yes I've searched.Also posted in lancerregister.

 

When we tuned my evo 7 years ago we found that the stock fuel pump was weak.

 

You need a tune, the car is obviously old and parts age and stop working. A new fuel pump would be on my list along with a tune.

 

If they are back to back runs it looks like it's been played with before, as there is normally a much more characteristic difference in AFR's due to lean spool, that and the fuel curve is very smooth.

 

That's what I thought grayw. The fuel pattern across the board...makes me think it's been at least tweaked at some point before. I bought the car used but the previous owner swore he didn't touch the stock map, well apart from the SAFC (which I already took off and bridged the air flow wire but I didn't solder tho). I did mention in lancerregister I found what looks like a broken head phone jack underneath the driver's carpet...don't know if its any help. Also when you say back to back did you mean one pull after another? If so, yes.

Yes I will definitely need a tune. Walbro may help richening it a bit but I don't want it be there to just masking the real problem. In fact, I've tried THREE used working pumps (2 E7, 1 E8) to no avail but once a friend's walbro in with 3bar set in fpr, the afr went pig rich! causing the car to loose hp! I'm interested in knowing what's causing it to lean. Will a blocked filter restrict the fuel flow, or is it something electrical perhaps? I don't have a multimeter but can anyone tell by just looking at the afr curve that the dual voltage pump is functioning? I've swapped the 2 relays under the dash and I'm about to source relay #3. Has anyone heard of a failed injector resistor pack in E7?

Things started to become a problem when I went for dynos and installed my 'worrying' aem wideband to check my afr. Been driving for about a year with no issue (apart from hesitation but cured with new IGR7AG plugs...don't know if its related)

Thanks all, sorry for the essay.

 

Fuel pump!!!

 

The split voltage looks to be working, it would not run into the 12's otherwise. Would look at the fuel map, as it looks like it's been mapped like that.
If they are back to back runs the lean spool has been disabled, as there would be around 1 to 1.3 afr's difference between the 1st and 3rd run.
You can bypass the fuel pump resistor so the pump see's full voltage, but 99% not the issue.

 

Glad to hear the voltage is working. I'm leaning towards the mapping issue but none of the so called evo gurus here in my areas ever believe me. I'll take your advice, I won't bother with the resistor bypass.
I have a spare E7 ecu I bought cheaply from a wrecker months ago. For someone without access to evoscan/tatcrix do you reckon it worths swapping over to see if the stock afrs behave as they should? AFAIK both ecus came with immobilisers disabled. Will it do more harm than good?

Any geekmapping 'seminar' in Kuala Lumpur by any chance grayw?...hehe

Thanks for the inputs nocabiwiksmx, evo8426 and Mauricio!

 

also check for boost leaks.

 

Would a boost leak show rich instead of lean chrisw? Or you mean exhaust leak? I had a nasty noise whereby my long shaft rubbed against my custom exhaust flanges not too long ago. I might as well check on that. Thanks!

 

Boost leaks normally make fuelling richer. If you have installed a walbro and it runs much richer, then keep it in there and tune to suit.
If I visit KL on holiday I'll let you know, it's on my list of places to go!

 

I haven't installed a walbro yet. It was my friends one I played with the other day. And that metal ring above the fuel housing was really annoying!,...but at least I don't have to drop the tank tho. I'm going to get the original walbro this weekend...gosh those chinese copies are everywhere!
I suppose I don't need a fpr, do I? The dual voltage will hopefully be able to avoid overrun, well in my case I do 'need' to overrun a bit. It's kinda hard to actually find tuners here who really into what they're doing if you know what I mean. Oh, should I bother with the ecu swap I mentioned above?

Cheers grayw! Give me a shout if you happen to be in KL or somewhere in those sunny beaches! You need a break from those cloudy English skies...hehe ta!